Counterweight device for roller curtains



Dec. 31, 1946. SQRRENTINO 2,413,471 I COUNTERWEIGHT DEVICE FOR ROLLER CURTAINS Filed Nov. 2, 1943 4 Sheets-Sheet 1 JW fi n Dec. 31, 1946.

L. SORRENTINO 2,413,471

vCOUNTERWEIGHT DEVICE FOR ROLLER CURTAINS Filed Nov. 2, 1943 4 Sheets-Sheet 2 Dec. 31, 1946. SORRENTINO I 2,413,471

COUNTERWEIGHT DEVICE FOR ROLLER CURTAINS Filed Nov. 2, 194-3 4 Sheets-Sheet 5 Elthnwm 9 6- SORRENTINO I 7 COUNTERWEIGHT DEVICE FOR ROLLER CURTAINS Filed Nov. 2, 194a 4 Sheets-Sheet 4 Patented Dec. 31, 1946 UNITED STATES PATENT OFFICE COUNTERWEIGHT DEVICE. FOR) ROLLER CURTAIN S Luis Sorrentino, Buenos Aires, Argentina ApplicationNovember 2, 1943, Serial n10-50839- This invention relatesto a counterweight device for roller curtains, and more particularly to a counterweight device for facilitating the operation of opening and closing blinds and the like.

Several elements andv devices have been suggested and. to a certain extent used heretofore for the'purpose of compensating the'weight of. the curtain-during the action-thereof, but inasmuch as" such devices are generally constituted by springs or simple counterweights, they onlycounteract theweight in certain positions of-the blind. Thus, in the caseof relativel'ylarge roller curtains, it isnecessary to use'a reductioncontrol, in the way of combination apparel capable of multiplying the forces with less speed in' order to overcome the resistanceof 'theblind or curtains.

Actual experiments have shown-.that in order to obtainthenecessary equilibrium of the counterweight relative to the curtain, it is'necessary that the pulley with which the weight is associated, should ha-ve a variable radius, and this is achieved by means of the present invention.

The device of the present invention comprises av pulley counterweight mechanismwherein thewinding base of the pulley isconstituted by a spiral groove or channelthe radius of which increases gradually from a' minimum section to the maximum periphery thereof and again decreases on the opposite facethercof', but with a shorter turn capableofj presenting a substantial diiierence relative tothe' path ofthe channel corre-- sponding'tothe main face thereof;

saidipulley is so combined that while it is fixed' to the winding. drum, it will act in combination therewith, in sucha' manner that the weight actingxby means of its cable in said channel of the pulley, willbehave as an element of substantially variable power; depending on the position in which. said. weight is hanging, since the lever radius'will be larger or smaller according t'o'-=thedirection ofzrotatioin Inasmuch as-the diameter of the'pulley: is calculated in accordance with theweightzofi the icurt'ainto' which the counterweight device is applied, this will" ensure a substantially stable .equilibriumfin every. position of the curtain;

Apart from v the foregoing, the" invention con-- templates: other-objects; among which may be citedythe provision of. a counterweight arrangement of relative and" graduali equilibrium throughout the-total opening-p01" closing-positions- 0f:the.blind.

Arfurther object of theinventioniis torprovid'e" direct control meanswhichxwill requirea mini- 7- Claims. (Cl.'160--33) which, on being placed in inoperative position will lock the entire. mechanism.

The. above andotheri objects and advantages of the present invention will become apparent from the course of the following. description, when read in'conjunction with the accompanying drawings illustrating the; invention by way of example and in a preferred embodiment.

In the drawings:

Fig; 1 is a' front View of'the blind in open position, showing the manner in which same is combined with the counterweightdevice.

Fig. 2 is a side View showing the weight depending from the channel of smaller section of the pulley.

Fig. 3' is a View similar to Fig. 1 but showing the blind in closed position, with the slats in spaced relation, at which time the weight of. the counterweight device is acting on the maximum turn of the spiral.

Fig. l'shows the same blind'in fully closed position, viz; with the slats juxtaposed and the weight thereof counterbalanced by the counterweight depending from the secondary spiral of the pulley.

Fig; 5is a cross-sectional view of the winding drum, taken along the line NN of Fig. 4.

Fig. 6 is a front view of the control device of the curtain, with the rosette of'the crank partiallybroken away so as to show the diiierent locking points; and

Fig. 715 a cross-sectional View of the same controld'evicek The same reference characters are used to indicate like or corresponding parts or elements throughout the different figures.

With reference to the drawings, a'indicates a blind, which in the present instance is constituted by a plurality of slats i joined together by link members 2 and forming an articulated assembly; which: may be wound on a drum 3 to whichzonerendioirtheblind is attached, the latter 3 sliding on a guide 4. Said drum 3 is fixed to a shaft 5 mounted on bearings 6 suitably located at each side of the frame in which the blind is to be mounted.

In the fully wound position shown in Fig. 1, the blind a ofiers torque relative to the drum 3, but when the blind is unrolled to the position shown in Fig. 3, the entire weight thereof depends on the radius of said drum thus necessi tating a counterweight which will counteract the load throughoutthe opening and closing range of the blind. In the position shown in Fig. 3, the

slats remain in spaced relation with each other,v

for ventilation and light purposes. This spacing of the slats may be cancelled through the action of the same drum which on further unwinding the blind will cause the juxtaposition of the slats I, thus bringing the blind to a fully closed position as shown in Fig. 4. In this instance, inasmuch as the slats are superposed relative to each other, the weight of the assembly will not depend on the radius of the drum.

According to the present invention, the curtain or blind a is balanced by means of the counterweight device constituted by the pulley b, cable 1 and weight 8. Said pulley b is fixed to the shaft 5 so as to act simultaneously with the drum 3.

As the blind a is closed or opened, the torque will be greater or smaller, which will depend on the portion of the blind depending from the drum 3, and therefore. said device should act in relation to the weight'oifered by the depending portion of the blind.

For this purpose. said pulley b is spiral-shaped,

having a channel 9 in which the cab e 1 is wound.

As clearly shown in Figs. 1 to 5. said channel 9 is spiral-shaped with a helical pitch, that is to say, that said channel 9, from the largest Or maximum turn 9 gradually decreases in radius until it reaches the smallest or minimum turn 9". Thus, when the Weight 8 depends, through cable 1, from the maximum turn 9', said weight will offer an efiect equivalent to the weight of the curtain a in its fully unwound position, and said channel 9 has a convolution with as many turns as revolutions the drum must eifect in order to fully wind or unwind the blind. Thus, when the blind is in fully wound or open position, as shown in Figs. 1 and 2 the cable 1 of weight 8 will be located within that portion of the channel corresponding to the smallest turn 9" so as to be in equilibrium with the blind which oifers substantiallv no weight in this position.

Apart from the spiral formed by channel 9, said pulley b is provided with a second channel l which extends from the maximum turn 9', describes a short path and ends at I 0, this latter spiral channel In constituting an extension opposite the main spiral channel 9. Thus, channel I!) is a secondary spiral but enables the adaptation of cable 1 so as to reduce the torque exerted by weight 8 in passing from said maximum turn to said secondary spiral.

, The secondary spiral determined by channel l serves to reduce the radius arm of the weight 8 on pulley b when the drum 3 is further actuated from the position of the blind shown in Fig. 3 to that illustrated in Fig. 4 where the slats are juxtaposed and, therefore, cease to gravitate on the radius of drum 3 until said gravitation is finally entirely counterbalanced when all the slats l are superposed. I..-

Said cable I is guided on a sheave ll rotatably mounted on a roll I 2 and slidable thereomisnras to guide the cable with said weight 8 during its travel by the different channels of both the main and secondary spirals.

For the purpose of operating the blind, shaft 5 is provided with a bevel gear [3 meshing with a gear l4 having fixed thereto a toothed wheel l5 which is connected by means of an endless chain IS with a control gear Wheel I1.

Said control wheel I! is fixed to shaft [8 mounted on bearings l9 and 20 located in a box 2| of the actuating or control device 0 which is embedded in the wall by means of anchoring members 22. Shaft l8 ends in a rosette 23 having pivoted thereto a crank 25 by means of pivot 24, so that upon displacing said crank 25 to the position shown in full lines in Fig. 7, it will serve to rotate the shaft l8 and, through toothed wheel I! and chain l 6, said rotary motion will be transmitted to wheel l5, the gear [4 of which will actuate the gear l3 and consequently shaft 5, drum 3 and pulley I), thus Winding or unwinding the blind, depending from the direction in which the crank is turned.

Upon placing the crank 25 in inoperative position shown in dotted lines in Fig. 7, same is secured by means of a button 26 arranged at the side of a groove 21 provided diametrically on said rosette 23 so as to accommodate said crank when the latter is in inoperative position, thereby giV- ing said rosette the appearance of a simple disc.

Said groove or recess 21 is provided with a pin 28 passing through the body of said rosette 23 and urged by a spring 29 so as to project from the bottom surface of said recess 21. Upon pressing said pin 28, overcoming the resistance of spring 29, the opposite end 28' thereof will extend outwardly of the rosette and enter one. of the holes 30 provided in a cup shaped element 3| fixed to the box 2| of the control device 0. Said holes 30 form an annular line. Consequently, upon placing the crank 25 in inoperative position as shown in dotted lines in Fig.7, pin 28 is pressed so that the end 28' thereof will enter one of said holes 30, thereby locking the rosette against movement and, consequently, the entire control mechanism of blind a will be prevented from moving either for opening or closing the blind. Thus, the inoperative position shown in dotted lines in Fig. 7 constitutes a safe means for looking the curtain in any position.

Upon placing crank 25 in operative position as shown in full lines in the same Fig. 7, said spring 29 will act to free the pin 28 from the corresponding hole 30, thereby releasing the entire mechanism and placing same in condition to control the curtain a by means of said crank 25.

Resuming, said pulley b with the two spiral channels 9 and l 0, and the associated cable 1 and weight 8, will act as an automatic regulator so as to maintain a constant counterweight equilibrium relative to the curtain a, inasmuch as the torque olfered by said weight 8 in combination with the pulley, starting from the smallest turn 9" corresponding to the fully wound position shown in Figs. 1 and 2, will be gradual and relative up to the maximum unwinding as shown in Fig. 3, when the weight of the entire curtain suspended from the radius of drum 3 is compensated by said weight 8 which is at this time gravitating on the maximum radius of the pulley, that is to say, on the turn 9' thereof. However, if the action of the control mechanism 0 is continued so that the drum 3 will rotate further in the same direction, the slats I will superpose, with the consequent torque reduction on the radius of drum 3, while 5, at-the same time cable 1 onda'ry spiral of channel" ID,- in such amannerthat upon reachingthe portion Hi, all the slats I will remain superposed-to each other without offering any torqueand, therefore, in complete equilibrium with thecounterweight;

It -is evident that in'carrying the invention into practice; several changes-and alterations will occur to thoseskilledin the art, without departing from the scope of the invention asclearly set forth in the appended claims;

I claim: I

1; A-counter-weight device for a roller slat blind. mounted on a drum supported by a shaft, the slats thereof being connected by means permitting separation, said device comprising a spiral pulley mounted on said shaft, a counterweight depending from a cable windable on said spiral pulley, the weight of said depending counterweight acting over the different radii of said pulley being in equilibrium with the unwound portion of the slat blind in the different winding positions thereof on said drum, said pulley having a main spiral corresponding in increasing radii to the radii of the winding roll of said slat blind, and a secondary return spiral continuing from the maximum turn of the main spiral, the decreasing radii of said secondary spiral corresponding with the transition from the position of maximum unwinding of the slat blind with the slats in maximum spaced relaw-ill' passon to the section and the bottom slat just touching a support,

to the position of juxtaposition of the unwound slats whereby the weight of the suspended portion of the blind is substantially counterbalanced by said counterweight.

2. A counterweight device for a roller slat blind mounted on a drum supported by a shaft, the slats thereof being connected by means permitting separation, said device comprising a spiral pulley mounted on said shaft, a counterweight depending from a cable windable on said spiral pulley, a sheave for guiding said cable, said sheave being rotatably and transversely slidably mounted on a sheave-shaft, the weight of said depending counterweight acting over the different radii of said pulley being in equilibrium with the unwound portion of the slat blind in the different winding positions thereof on said drum, said pulley having a main spiral corresponding in increasing radii to the radii of the winding roll of said slat blind, and a secondary return spiral continuing from the maximum turn of the main spiral, the decreasing radii of said secondary spiral corresponding with the transition from the position of maximum unwinding of the slat blind with the slats in maximum spaced relation and the bottom slat just touching a support, to the position of juxtaposition of the unwound slats whereby the weight of the suspended portion of the blind is substantially counterbalanced by said counterweight.

3. A counterweight device for a roller slat blind mounted on a drum supported by a shaft comprising a spiral pulley mounted on said shaft, a counterweight depending from a cable windable on said spiral pulley, the weight of said depending counterweight acting over the different radii of said pulley being in equilibrium with the unwound portion of the slat blind in the different winding positions thereof on said drum, and a control mechanism for said dru-m comprising a box, bearing members therein, one of said bearings being in the form of a cup-shaped member and provided with holes, a second shaft in said bearing one end of said second shaft extending beyond the exterior face of the cup and terminating in a rosette,

counterweight depending the weight of said dependsai'd holes being arranged in anannular lin concentricto'th'e axis-of rotation of the rosette, a groove-therein, acrank pivoted to the'rosette to effect rotation of? said second shaft, said crank beihg-adapted'to befolded in said groove when'in inoperative position, a spring-urged pin within said groove out-of engagement with th holes of said cup whenthe crank isin operative position, and inengagement withone of said'holes when the crank is in inoperative position in said'groove and'means'totransmit the rotation of said Second shaftto the-windingdrum of the roller slat blind.

a. A counterweight device for a roller slat blind mounted on a drum supported by a shaft comprising a spiral pulley mounted on said shaft. a from a cable windable on said spiral pulley, ing counterweight acting over the different radii of said pulley being in equilibrium with the unwound portion of the slat blind in the different winding positions thereof on said drum, and a control mechanism for said drum comprising a box, bearing members therein, one of said bearings being in the form of a cup-shaped member and provided with holes, a second shaft in said bearing, one end of said second shaft extending beyond the exterior face of the cup and terminating in a rosette, said holes being arranged in an annular line concentric to the axis of rotation of the rosette, a groove therein, a crank pivoted to the rosette to effect rotation of said second shaft, said crank being adapted to be folded in said groove when in inoperative position, means mounted in the groove in said rosette and engageable in the holes in said cup-shaped member to lock the second shaft and rosette against rotation, means urging said latter means out of such locking position, said first means being engageable by said crank when in an ino erative position in the groove to force same into the locking position, and means for transmitting the rotation of said second shaft to the winding drum of the roller slat blind.

5. In a counterweight device for use in controlling a winding drum mounted on a shaft and adapted to receive a lurality of serial y connected members, a pulley mounted on said shaft, said pulley having a pair of spiral grooves therein, one of said grooves increasing from a minimum up to a maximum radius and the ot er groove decreasing from the same maximum down to a minimum, a cableattached at one end to the spiral pulley and a counterweight attached to said cable, the convolutions of one of said spiral grooves on the pulley being adapted to increase the radius arm and hence the torque on the shaft as the winding drum is rotated to unroll a greater length of the serially connected me bers and operating means connected to said shaft for rotating same, said cable being shiftable from the first to the second groove for relievin the drum of the weight of the slats.

6. In a counterweight device for use in controlling a winding drum mounted on a shaft and adapted to receive a plurality of serially connected members, a pulley mounted on said shaft, said pulley having a pair of spiral grooves therein, one of said grooves increasing from a minimum up to a maximum radius, the second of said grooves decreasing from the same maximum down to a minimum, a cable attached at one end to the spiral pulley and a counterweight attached to the cable,

a guide roll mounted in parallel relationship to said shaft, a sheave slidable on said guide roll,

said cable extending over the sheave, the convolutions of one of the spiral grooves on said pulley being adapted to increase the radius arm and henc the torque on the shaft as the winding drum is rotated to unroll a greater length of the serially connected members, and operating means connected to the shaft for rotating same, said cable being shiftable from the first to the second groove for relieving the drum of the-weight of the slats.

7. In a control device for a slat-type blind adapted to be coiled around and un-coiled from a shaft, a second shaft perpendicular to said shaft, driving connections between the shafts, a. frame member mounting said second shaft, a circular row of holes in said frame member concentrically disposed with respect to the second shaft, a rosette of substantially circular shape in said second shaft, a spring urged stop pin mounted in said rosette and adapted to rest in said holes, a handle of length approximately equal to the diameter of the rosette, said handl being pivoted to the rosette adjacent the periphery of the latter and foldable to overlie the stop pin.

- LUIS SORREN'IINO. 

